Scanning electron microscopy of experimental Trichophyton mentagrophytes infections in guinea pig skin.

Trichophyton mentagrophytes invasion of guinea pig skin was examined by scanning electron microscopy. Biopsies were obtained daily for 12 days from experimental infection sites. Dermatophyte invasion, examined in detail by scanning electron microscopy of cross-sectioned, prefixed skin was evidenced by: the appearance of hyphae within the stratum corneum; follicular invasion by hyphae, which remained initially within the follicle wall; emergence of the hyphae from the wall into the follicular canal; proliferation of the fungus down the follicle, with furrowing of the follicle wall and hair shaft cuticle; penetration of hyphae into the hair shaft by subcuticular and transcuticular routes; and massive peripilar hyphal proliferation with arthrosporogenesis. A three-dimensional perception of the invasion sequence of a dermatophyte in guinea pig skin was obtained by scanning electron microscopy.